Millions of syringes are used daily throughout the United States relative to injecting humans as well as animals with various types of solutions and medications. Syringes for humans are also used in large quantities by victims of diabetes and a very high percentage of such victims require the injection of Insulin. It is possible for such victims to have such injections occur at home rather than in a doctor's office but many individual victims are incapable of psychologically overcoming the hesitancy of injecting themselves with a hypodermic needle.
To overcome the foregoing situation and particularly to provide syringe-injecting devices which can be operated by victims themselves to effect their own injections by themselves, a number of instruments have been developed to support needle-type syringes and by means of springs or otherwise cause an instantanous projection of the needle of the syringe into their own flesh. One example comprises U.S. Pat. No. 3,677,246, dated July 18, 1972, to Stein and also British Pat. No. 780008, dated July 31, 1957, to Palmer. In said U.S. patent, a spring effects ejection of the contents of the syringe after insertion of the needle and in said British patent, a manually operated plunger effects such projection of the contents of the syringe following insertion of the needle.
A number of developments also have provided mechanism in which a supporting frame for a syringe has a handle similar to a pistol grip and operation of trigger-like members causes movement of the plunger of the syringes to effect ejection of the contents of the syringe. Typical examples of such devices comprise U.S. Pat. No. 3,160,156, dated Dec. 8, 1964, to Tyler; U.S. Pat. No. 3,353,537, dated Nov. 21, 1967, to Knox et al.; Austrian Pat. No. 212,625, dated Dec. 27, 1960, to Hauptner; and Swiss Pat. No. 449,180, dated Nov. 8, 1966, to Sanz.